Mannan, of yeast

Mannam—These are often present in wood, especially of conifers, and they are difficult to separate out. The mannans of pine and spruce are built of mannose molecules joined in straight chains of about 200 residues. The mannan of yeast, on the other hand, is highly branched and is not homogeneous. The number of molecules of mannose in these chains varies from 90 to 830. 

D. Page, D. Zanini, and R. Roy, Macromolecular recognition Effect of multivalency in the inhibition of binding of yeast mannan to concanavalin A and pea lectins by mannosylated dendrimers, Bioorg. Med. Chem., 4 (1996) 1949-1961. 

Y. Li, X. Zhang, S. Chu, K. Yu, and H. Guan, Synthesis of cluster mannosides via a Ugi four-component reaction and their inhibition against the binding of yeast mannan to concanavalin A, Carbohydr. Res., 339 (2004) 873-879. 

The structure of mannose-rich polysaccharide core in GL4 is close to that of yeast mannan (from Saccharomyces cerevisiae), which was inactive for IL-6 induction in a human peripheral whole-blood cells test system. This fact suggests that not the mannose moieties but other components, such as the lipophilic moiety and/or phosphates, are important for the activity. The lipophilic products in HF-hydrolysate of GL4 were then analyzed. In addition to peaks corresponding to the known fatty acids (C16 0, C18 1), two other unknown ion peaks at m/z 330 and 356 were found by FAB-MS (data not shown). 

Fig. 2.—Diagram of Hypothetical Structure of Yeast Cell-wall JPhosphoric diester links are represented by —P— (E) is 0-D-fructofuranosidase is D-glucan is D-mannan and S is sulfur. From Ref. 117 printed here by permission of Cambridge University Press.]...

The structures of the cell-wall D-mannans of several other yeasts have been investigated381 by use of this exo-a-D-mannanase. Five were degraded to the (l->6)-a-D-mannan chain. Those which contained jB-linked d-mannosyl units or a-D-galactosyl groups in the side chains were not significantly hydrolyzed. However, removal, by partial hydrolysis with acid, of the a-D-galactosyl units from five galactomannans, and of /3-linked D-mannosyl units from three other D-mannans, rendered these polysaccharides partially susceptible to hydrolysis by exo-a-D-mannanase, consistent with an a-linked-D-mannan structure. 

Antibodies can be used for detection of carbohydrate sequences in biological materials. For example, a mannotetraose (Manal-3Manal-2Manal-2Man) obtained by selective acetolysis of yeast mannan was derivatized with phenethylamine and diazotized to edestin (3). Specificity of the anti-mannotetraose antibodies obtained was studied by the radioimmunoassay methods just described. Results of these studies are summarized in Table II. 

Many pioneer structural investigations were carried out in other groups of polysaccharides, notably on inulin, on the xylan from esparto, on the mannan from yeast and on a series of bacterial polysaccharides amongst the latter were included somatic and lipoid-bound polysaccharides from M. tuberculosis. Noteworthy also was the work on the dextran produced by strains of Leuconostoc, which is showing grqat promise as a blood plasma substitute. 

A number of yeast mannans containing a- and jg-D-mannopyranosyl units exist, and the latter structure was detected by distinctive, H-l signals in H-n.m.r. spectra at fields higher than 8 5.43 (see Table IV). The mannans from Pichia pastoris and Citeromyces matritensis respectively contain structures 13 and 14. Main chains that were isolated... 

The Percentage Content of N-Acetyl Groups in (2-Acetamido-2-deoxy-D-gluco)-mannans from Yeasts, Based on Magnitude of NAc Signals in Proton-N.m.r. Spectra... 

A. B. Tsiomenko, I. Augustin, V. M. Vagabov and I. S. Kulaev (1974). The interrelationship of the metabolism of inorganic polyphosphates and mannan in yeasts (in Russian). Dokl. Akad. Nauk SSSR, 215, 478-482. 

V. M. Vagabov, A. B. Tsiomenko and Yu. A. Shabalin (1973). The Study of Interaction of the Metabolism of High-Molecular Polyphosphates and Mannan in Yeast (in Russian), ONTI NCBI Akad. Nauk SSSR, Pushchino, pp. 144-155. 

Fluorescein- and mercury-labelled con A386-388 have been used to demonstrate the presence of D-mannan in yeast cell-walls386,387 and in... 

Approximately one atom of Mn2+ and 2.5 atoms of Ca2+ are bound per lectin molecule.141 (Ethylenedinitrilo)tetraacetate (EDTA) inhibits both hemagglutination and precipitation of yeast mannan.456 Successive dialysis against EDTA and M acetic acid removed most of the Ca2+, but did not change the Mn2+ content. The apoprotein failed to precipitate D-mannan, and the hemagglutination titer was decreased458 by 75%. 

The main structural constituents of Saccharomyces cerevisiae yeast cell wall are glucans and mannans with a minor proportion of chitin (Walker 1998). Manno-proteins are located in the outer layer of the yeast cell wall and determine most of the surface properties of the wall. Vasserot et al. (1997) studied the capacity of yeast lees to adsorb anthocyanins in an attempt to reduce the detrimental effects of charcoal on the color of red musts and wines. Experiments based on model wine solutions revealed that yeast lees possess a greater affinity for anthocyanins than... 

Yeast mannan is an amorphous, homogeneous polysaccharide with a D. P. of about 500. The proposed structure of this mannan is a long chain, with radiating side-chains of one or two D-mannopyranose units. In this mannan, 2 —> 1, 3 —> 1, and 6 — 1 linkages have been found. The mannan of the seaweed Porphyra umbilicalis contains chiefly 4 —> 1 /3-d linkages, and is of the branched-chain type with about one branch for each 12 D-mannose residues. 

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